diff --git a/gcc/testsuite/gcc.c-torture/compile/20050423-1.c b/gcc/testsuite/gcc.c-torture/compile/20050423-1.c
new file mode 100644
index 00000000000..fee5eb9093e
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/20050423-1.c
@@ -0,0 +1,16 @@
+/* PR tree-optimization/20742 */
+
+int
+foo (int x, int y)
+{
+  register int a = y + 57;
+  register int b = y + 31;
+
+  while (x-- > 0)
+    {
+ #define TEN(x) x x x x x x x x x x
+      TEN (TEN (a += b; b -= a;))
+      TEN (TEN (a += b; b -= a;))
+    }
+  return a + b;
+}